Strand drawing and crimping treatment

ABSTRACT

Textile strands are subjected to a gear-crimping operation and a compressive crimping operation in succession, optionally preceded by a strand-drawing operation.. Rotatable gear-crimping elements preferably are oriented with their axes at an acute angle to the axes of rotatable strand-drawing and/or compressive crimping means.

United States Patent Stanley 5] Dec. 9, 1975 [5 STRAND DRAWING AND CRIMPING 3,234,626 2/1966 Faria 28/1.3

TREATMEN 3,359,609 12/1967 lwnicki et a].

. 3,423,806 1/1969 Dickins 28/l.6 Inventor: Robert y, Medla, 3,454,998 7/1969 Satterwhite 28/72.14 x

3,462,814 8/1969 Stanley 1 28/72.l4 [22] Flled Sept' 1970 3,473,316 10/1969 Jenkins et a1. 28/72.14 X [21] Appl. No.: 68,960 FOREIGN PATENTS OR APPLICATIONS R la pp ati n ata 2,000,559 1/1970 France 28/1.6 [63] Continuatiomimpart f S No 815 425 April 11 291,120 5/1928 United Kingdom 28/1.3 19 9 Pat N 3 570 0 4 and a continuationqmpart 850,033 9/1960 United Kmgdom 28/l.3 of Ser. No. 822,429, May 7, 1969, Pat. No. 3,570,083, and a continuation-in-part of Ser. No. Primary ExaminerR0bert R. Mackey 835,883, June 1969, at- Attorney, Agent, or FirmChar1es A. McClure [57] ABSTRACT g [58] Field Of Search 28/1.3, 72.11, 1.6, 72.14 T Strands are 9 a tion and a compresslve cnmpmg operation in succes- [56] References Cited sion, optionally preceded by a strand-drawing operation.. Rotatable gear-crimping elements preferably are UNITED STTES PATENTS oriented with their axes at an acute angle to the axes 2,326,174 8/1943 Rutishauser 28/L3 X P of rotatable trandqjrawing and/ compressive crimp- 2,686,339 8/1954 Holt 28/72.14 i means 3,099,064 7/1963 Haynes 28/l.3 3,111,740 11/1963 Stanley 28/1.6 6 Claims, 5 Drawing Figures U.S. Patent Dec. 9 1975 ROBERT K. STANLEY /jc? STRAND DRAWING AND CRIMPING TREATMENT Reference is made to my pending patent applications, Ser. Nos. 815,425 filed Apr. 11, 1969, now Pat. 3,570,084; 822,429 filed May 7, 1969, now Pat. 3,570,083; and 835,883 filed June 9, 1969 now Pat. 3,559,254. The benefit of the filing of the latter two thereof of which the present application is a continuation-in-part and of their respective predecessor applications, with which there was continuity of disclosure is claimed for this application. U.S. Pat. No. 3,570,083 is a continuation-in-part of U.S. Pats. Nos. 3,462,814 and 3,412,815, which are continuations-in-part of Pat.

No. 3,376,622, itself at least in part a continuation of application Ser. No. 216,524 filed Aug. 13, 1962 and subsequently abandoned. U.S. Pat. No. 3,559,254 is a continuation-in-part of application Ser. No. 650,762 filed July 3, 1967 (and subsequently abandoned) as a continuation-in-part of U.S. Pat. No. 3,500,518, which is a continuation-in-part of U.S. Pat. No. 3,386,142, itself a continuation-in-part of U.S. Pat. No. 3,279,025.

This invention relates to treatment of textile strands wherein crimped configuration is imparted thereto, especially wherein multiple crimping follows drawing thereof in continuous manner.

Known techniques for crimping textile strands include, inter alia, methods of imparting generally sawtooth or zigzag crimped configurations thereto. One way to do so is by passing a strand in contact with the teeth of at least one rotatable gearlike element against which it is forced by a cooperating movable element, which may be a belt or an intermeshing gearlike element, for example, usually resulting in a regular crimp characterized by substantially equal leg lengths. Another way is by forcing the strand into a temporarily confining chamber containing an accumulation of strand against which the entering strand buckles, usually into a less regular crimp characterized by a substantial range of leg lengths as well as a greater range of angular distribution, both within any given plane and extraplanar, as compared with the gear-crimped configuration (even when multiple gear-crimping passes are employed). It is also known to draw textile strands to increased length before crimping them.

A primary object of the present invention is improved sawtooth crimping of textile strands.

Another object is a novel multiple crimping process for textile strands. A

A further object is draw-crimping of textile strands.

Other objects of the present invention together with means and methods for attaining the various objects, will be apparent from the following description and the accompanying diagrams.

FIG. 1 is a side elevation, partly schematic, of appa ratus according to this invention;

FIG. 2 is a side elevation of apparatus components adapted to be substituted for one or more of the components in the preceding view;

FIG. 3 is a side elevation of certain other of the components of FIG. 1 showing an alternative orientation for some thereof;

FIG. 4 is aside elevation of the apparatus components of FIG. 3 plus an added component; and

FIG. 5 is a side elevation of the apparatus components of FIG. 3 with certain thereof in yet another orientation.

In general, the objects of the present invention are accomplished, in treatment of textile strands wherein crimped configuration is imparted thereto, by first drawing and thereafter gear-crimping a textile strand and then compressively crimping it, all as a continuous operation. In particular, the invention comprehends treating a textile strand by drawing it to increased length, imparting a regular sawtooth crimp to the drawn strand by gear-crimping it, and then imparting a less regular sawtooth crimp to the strand by compressively crimping it. Apparatus features are described below with reference to the diagrams.

FIG. 1 shows textile strand being unwound from supply package 11 thereof and proceeding through a drawing means, in which it is drawn to increased length, including an initial set of rolls 12, 13 and a final set of rolls 16, 17 flanking optional draw pin 14. The strand usually wraps several times around each set of rolls and once about the draw pin. From roll 16 the drawn strand (designated as 10) proceeds to gearcrimping means and more specifically between intermeshing gears 18, 19 within enclosure 20, after which it is designated as 10". Then it passes to compressive crimping means and more specifically through the nip of pair of rolls 22, 23 and into stuffing chamber 24, within which it is confined temporarily upon coming into contact with an accumulation of strand previously fed thereinto and not yet withdrawn. After a period of temporary confinement in the chamber the resultant strand (designated as 10") is withdrawn, through zone 26 and over idler roll 27, and onto windup package 29 driven by surface contact with windup drive roll 28, which may be helically grooved to traverse the strand passing over it.

Motor 31, at the lower left in FIG. 1, is interconnected mechanically (as indicated by broken lines) to transmissions for the various driven rolls and similar elements. Thus, transmission 33 interconnects godet rolls 12 and 16 of the initial and final sets of draw rolls with the motor and ensures that the surface speed of final roll 16 is sufficiently greater than that of initial roll 12, to assure the desired ratio of final or drawn length to initial or undrawn length. Transmission 35 transmits motive force to one or both of intermeshing gears 18, 19 of the gear-crimping means at a speed approximating the speed of the final draw roll, and transmission 37 transmits motive force to one or both of feed rolls 22, 23 of the compressive crimping means at approximately the same speed; preferred speed relationships are set forth more definitely below. Transmission 39 likewise interconnects windup drive roll 28 to the motor so as to provide motive force to strand windup package 29.

It will be understood that strand supply package 11 may be replaced by any suitable source of strand to be treated, not only any type of package but also freshly formed strand, if desired. Thus, FIG. 2 shows extrusion head 41 supplied with fiber-forming polymer and having spinneret 42 through which the polymer is extruded in a multiplicity of filamentary streams 50, which solidify into individual filaments and are brought together by pair of rolls 51, 52 into strand 100, part of the subsequent path of which is omitted as indicated by broken lines. The strand passes about a subsequent roll from which it may go directly to the initial set of rolls in the draw section of FIG. 1 in place of strand 10.

It will be observed that the axes of intermeshing gears 18, 19 in FIG. 1 are oriented in a plane parallel to the plane of the axes of feed rolls 22, 23 but at an acute angle thereto about the strand path. An angle of about 45 is preferred in the practice of this invention. However, where design limitations or other conditions dictate to the contrary, such angle may be eliminated and the gear axes be oriented wholly parallel to the feed roll axes, as shown in FIG. 3.

If it is desired to pass the strand between the gears more than once, this may be accomplished through use of separator roll 17, shown in FIG. 4. Such separator roll functions like separator rolls l3 and 17 for godet rolls 12 and 16 in the draw section, usually being mounted on a canted axis to assist in keeping the individual wraps separate.

Alternatively, the axes of intermeshing gears 18, 19 may be perpendicular to the axes of feed rolls 22, 23 about the strand path, preferably without disturbing the aforementioned planar parallelism, as shown in FIG. 5. In that view gear 19 hides gear 18, as well as separator roll 17, if used.

Operation of the present invention is readily understood. Textile strand supplied in suitable manner to the drawing means is drawn thereby to increased length and, notwithstanding that the step may be considered colddrawing, is heated thereby and may be heated otherwise to facilitate drawing, as by heating of the draw pin or initial godet roll 12, which may be heated internally as by circulation of hot fluid or by location of electrical resistance elements therein. Final godet roll may be heated likewise to prevent the strand from cooling before being crimped, which is also the purpose of the enclosure shown schematically about the gearcrimping means.

The latter enclosure may extend further in either or both directions along the strand path, from the drawing means to the compressive crimping means, for like reasons. Additionally, rotary members of either or both crimping means may be heated to maintain the strand temperature. An electrical heating arrangement for the feed rolls of a stuffer-crimper, suitable also for draw rolls or gearcrimping elements, is disclosed in my U.S. Pat. No. 3,111,740.

Gear-crimping of the strand is shown more clearly in FIG. 4 than in FIG. 1 because of the oblique orientation of the gears in the latter and the use of several wraps by means of a separator roll in FIG. 4. Succesive increments of the strand length are pressed in opposite directions by the teeth of the respective gears and into the space between adjacent teeth of the opposite gear.

This produces a regular sawtooth or zigzag deformation or crimp in the strand configuration.

Then the strand is forcibly fed into the stuffing chamber of the compressive crimping means. As it comes into contact with an accumulation of strand already therein it buckles into sawtooth or zigzag configuration of less regular leg length, angular distribution, or related characteristics than resulted from the gear crimping. The overall result is a composite crimp with both regular and more clearly random characteristics.

The preferred angular orientation of rotary elements in the respective crimping means about the strand path is further beneficial in enhancing the threedimensionality of the resulting crimp, as is desirable for many or most, if not all, kinds of strands and uses thereof. The crimped strand may be aftertreated in zone 26 to vary its tension, temperature, or other characteristics, as by stepwise heat relaxation according to my U.S. Pat. No. 3,221,385.

The compressive crimping means may comprise almost any type of stuffer crimper, but one with an openended stuffing chamber is preferred, such as that disclosed in my U.S. Pat. No. 3,279,025. Synchronization of windup speed may be largely dispensed with, and overall crimp may be controlled, by suitable preselection of speed or tension, as disclosed in my U.S. Pat. Nos. 3,386,142 and 3,500,518, respectively. Alternatively, conventional synchronization means may be used, whereupon fluid-controlled synchronization according to my U.S. Pat. Nos. 3,388,440 and 3,280,444 is preferred.

It will be apparent that predrawn strands may be crimped according to the present invention, but a continuous draw-crimping process is preferred as conducive to more stable final configuration. Moreover, as suggested by FIG. 2 and discussion thereof, the present invention permits a continuous extrude-draw-crimpwind operation, with resulting overall economies. Other advantages and benefits of this invention will accrue to those who undertake to practice it. The adiabatic or constant-temperature principles of my U.S. Pat. No. 3,348,283 are applicable, and herein the strand preferably is maintained at substantially constant temperature from drawing to compressive crimping. Also pertinent are the overall draw-crimping considerations disclosed in my U.S. Pat. Nos. 3,462,814 and 3,462,815.

The present invention is preferably practiced in accordance with the disclosure of my last mentioned patent directed to underfeed of a textile strand from the drawing means to the crimping means. However, the feed ratio need not be uniform throughout. Thus, while an overall underfeed from the drawing means to the feed rolls of the compressive crimping means is preferred (i.e., higher feed roll speed than final draw roll speed, at essentially non-slipping contact with the strand), the various transmissions may be adjusted so that there is an overfeed at one side or the other (but not both sides) of the gear-crimping means. Preferred conditions for nylon are for about 6-:3 percent underfeed from the drawing means to the gear-crimping means and then, in view of the distortion imparted thereby, a few (but lesser) percent overfeed from the gear-crimping means to the compressive crimping means. However, different strands may work best at different speed ratios and some may require underfeed throughout.

Textile strands, as defined herein, include monofilament and multifilament yarns; fibrillated or fibrillatable bands, ribbons, or tapes, whether preslit or not; and other funicular materials of compositions suitable for textile uses. Such compositions usually are thermoplastic and range from linear organic polymers, including copolymers and interpolymers, to glass. A prominent example is nylon, and many suitable organic compositions are listed in my last mentioned patents.

Certain modifications of the preferred embodiment of this invention have been suggested above, and other modifications may be made, as by adding, combining, subdividing parts or steps or substituting equivalents therefor. The invention itself is defined in the following claims.

I claim:

1. Treatment of drawable textile strands, comprising first drawing a textile strand to increased length, thereafter imparting a regular sawtooth crimp to the drawn strand by gear-crimping it, and then imparting a less regular sawtooth crimp to the strand by compressively crimping it, including the step of heating the strand before the gear-crimping step and maintaining it hot until the compressive crimping step, wherein the strand is maintained at substantially constant temperature from drawing to compressive crimpingl 2. In treatment of textile strands in three successive steps of drawing a textile strand to increased length, gear-crimping the strand, and stuffer-crimping the strand, the improvement wherein the strand speed in the respective steps is controlled, the drawing step is completed before beginning the gear-crimping step, and the strand speed at the conclusion of the drawing step is less than the strand speed at the beginning of the stuffer-crimping step. i

3. Strand treatment according to claim 2, wherein the ratio of strand speed from the drawing step to the gearcrimping step is maintained lower than the ratio of strand speed from the gear-crimping step to the compressive crimping step.

4. Strand treatment according to claim 2, wherein the ratio of strand speedfromthe drawing step to the gearcrimping step is maintained less than unity.

5. Strand treatment according to claim 2, wherein the ratio of strand speed from the gear-crimping step to the compressive crimping step is at most unity.

6. Strand treatment according to claim 2, wherein the ratio of strand speed from the gear-crimping step to the compressive crimping step is greater than unity. 

1. Treatment of drawable textile strands, comprising first drawing a textile strand to increased length, thereafter imparting a regular sawtooth crimp to the drawn strand by gearcrimping it, and then imparting a less regular sawtooth crimp to the strand by compressively crimping it, including the step of heating the strand before the gear-crimping step and maintaining it hot until the compressive crimping step, wherein the strand is maintained at substantially constant temperature from drawing to compressive crimping.
 2. In treatment of textile strands in three successive steps of drawing a textile strand to increased length, gear-crimping the strand, and stuffer-crimping the strand, the improvement wherein the strand speed in the respective steps is controlled, the drawing step is completed before beginning the gear-crimping step, and the strand speed at the conclusion of the drawing step is less than the strand speed at the beginning of the stuffer-crimping step.
 3. Strand treatment accordIng to claim 2, wherein the ratio of strand speed from the drawing step to the gear-crimping step is maintained lower than the ratio of strand speed from the gear-crimping step to the compressive crimping step.
 4. Strand treatment according to claim 2, wherein the ratio of strand speed from the drawing step to the gear-crimping step is maintained less than unity.
 5. Strand treatment according to claim 2, wherein the ratio of strand speed from the gear-crimping step to the compressive crimping step is at most unity.
 6. Strand treatment according to claim 2, wherein the ratio of strand speed from the gear-crimping step to the compressive crimping step is greater than unity. 